It has been previously known to mount a subframe on a vehicle body via resilient bushes, and to pivotally attach the inner ends of the lower arms of a wheel suspension system to the subframe, for instance, as is disclosed in Japanese utility model application No. 02-38221. In such an arrangement for supporting a wheel suspension system, a pair of plate members, which extend laterally of the vehicle body, and spaced from each other, are attached to the lower surface or the side surface of the subframe to define a beating portion, on each side of the vehicle body, and the inner end of the lower arms of the vehicle suspension systems are pivotally attached to the corresponding bearing portions via bushes.
However, the beating portions, which extends from the subframe in the manner of cantilevers, tend to be low in rigidity so that the beating portions are not effective in shutting off the noises and sounds transmitted from the road surface from the passenger compartment. It is conceivable to reinforce the beating portions, but it will add weight to the subframe, and increase the effort and cost required to fabricate the subframe assembly.